This invention relates generally to pressure activated seals, and more particularly relates to a pressure activated seal between two adjacent surfaces, such as between pipes or tubes arranged coaxially one within the other, or adjacent substantially parallel surfaces of two plates, for example.
Seals and gaskets such as O rings are commonly used to seal two adjacent surfaces of pipes or tubes arranged coaxially one within another. Such seals or gaskets are commonly used to seal the outside surface of an inner, relatively smaller diameter tube and the inside surface of an outer, relatively larger diameter tube disposed over the smaller tube, or two flat surfaces. In the case of two adjacent pipes or tubes arranged coaxially one within another, the smaller tube usually has a groove on the outside circumferential surface in which an O ring is inserted. The outside diameter of the O ring is typically slightly larger than the inside diameter of the outer tube, causing a slight compression of the O ring when the outer tube is slipped over the smaller tube, and forming a “seal” that stops liquid or air from passing between the two pipes or tubes. In some cases the inside diameter of the outer tube can become enlarged, for many reasons, particularly if one or both of the inner or outer tubes is eccentric (i.e., not round), or expands, because it made of expandable materials such as plastic, or due to heating, for example. Similarly, spacing between adjacent substantially parallel surfaces of two plates can become enlarged or distorted, such as due to warping of either of the plates, wear, or heating, for example.
It would be desirable to provide a pressure activated seal that can provide a seal between two adjacent surfaces, such as between inner and outer pipes or tubes arranged coaxially, or adjacent substantially parallel surfaces of two plates, for example, to overcome eccentric inside diameters, expanding tubing and other odd shapes, such as oval, square, hexagon or other similar shapes of pipes or tube, as well as warping of adjacent substantially parallel surfaces of adjacent plates having flat or curved shapes. The present invention meets these and other needs.